高突矿井采空区卸压瓦斯富集区的识别和富集区内抽采钻孔的布置对治理高突工作面瓦斯超限和采空区卸压瓦斯抽采具有重要意义。采用物理相似模拟和理论分析对高突矿井采空区卸压瓦斯富集区范围进行研究，基于“三带”理论和“椭抛带”理论，提出逐步精准辨识高突矿井采空区卸压瓦斯富集区的判别方法，并创新椭抛带微分扫掠数值建模方法；采用RSM-BBD（Response Surface Methodology Box-Behnken Design）方法设计试验，运用Fluent软件对卸压瓦斯抽采参数进行数值模拟研究，分析各单因素和交互因素对抽采效果的影响，拟合出各层位抽采参数与上隅角瓦斯体积分数的回归模型，得出各层位最优抽采钻孔参数，并开展数值模拟对比验证最优参数抽采效果；最后根据高突矿井采空区卸压瓦斯富集区精准识别和富集区内钻孔参数优化结果进行高位定向钻孔现场抽采试验。结果表明：采空区存在“卸压瓦斯存在区”、“椭抛带形运移活跃区”和“环形卸压瓦斯富集区”；单因素对同一垂距下环形富集区内抽采效果影响程度依次为：钻孔直径>钻孔平距>抽采负压，抽采负压和钻孔平距的交互作用对上隅角瓦斯体积分数的影响也较为明显；优化抽采参数后，试验工作面抽采期间回风流和钻场总抽采管内瓦斯体积分数整体呈下降趋势，回风流平均瓦斯体积分数为0.32%，钻场总抽采管内平均瓦斯体积分数为12.95%，工作面瓦斯得到有效控制。

It is of great significance to identify the enrichment zone of relieved methane in the goaf of high outburst mine and to layout the drainage boreholes in the enrichment zone for controlling the methane overrun in the high outburst coal face and extracting the methane in the goaf relief area. The scope of relieved methane enrichment zone in the goaf of high outburst mine was studied by physical similar simulation and theory analysis. Based on the theory of “three zones” and “elliptic paraboloid zone”, the discriminant method of gradually and accurately identifying relieved methane enrichment zone was put forward, and the differential sweep numerical modeling method of elliptic paraboloid zone was also innovated. Based on the RSM-BBD(Response Surface Methodology Box-Behnken Design)method, the experiment was designed, and the numerical simulation of methane extraction parameters was carried out by using Fluent software. The influences of single factor and interaction factor on the extraction effect were analyzed, and the regression model between the extraction parameters of each layer and the methane concentration in the upper corner was fitted to optimize the optimal drainage borehole parameters of each layer. Finally, according to the accurate identification of relieved methane enrichment area and the optimization results of drilling parameters in the enrichment area, the field drainage test of high position directional drilling was carried out.The results show that there are “relieved methane existing zone”, “elliptic paraboloid zone type active migration zone” and “relieved methane annular enrichment zone” in goaf. The influence degree of single factor on the drainage effect in the annular enrichment area with the same vertical distance is as follows: the drill diameter>drill horizontal distance>drainage negative pressure, and the interaction between the drainage negative pressure and the drill horizontal distance also has an obvious influence on the methane concentration in the upper corner. After optimizing the extraction parameters, the gas concentration in the return air and the total drainage pipe of the drilling field showed a downward trend during the drainage period of the test working face. The average gas concentration in the return air was 0.32%, and the average gas concentration in the total drainage pipe of high position directional drilling field was 12.95%.Methane in the coal face is effectively controlled.

1 试验工作面概况及采空区卸压瓦斯富集区判定

   1.1 试验工作面概况

   1.2 覆岩裂隙演化及采空区卸压瓦斯存在区识别

   1.3 椭抛带形瓦斯运移活跃区判定

   1.4 采空区环形卸压瓦斯富集区辨识

2 模拟模型建立及试验优化设计

   2.1 数值模拟模型建立

   2.2 钻孔数量的确定

   2.3 钻孔抽采参数优化设计

3 模拟抽采效果分析及参数优化

   3.1 主要因素对抽采效果的影响

   3.2 回归模型及模型验证

   3.3 抽采钻孔最优参数确定

   3.4 抽采效果对比

4 现场试验

   4.1 现场试验钻孔施工概况

   4.2 试验抽采效果

5 结论